STAPHYLOCOCCAL ALPHA TOXIN *

Ever since its detection toward the end of the 19th Century, staphylococcal alpha toxin has been under frequent if not continuous scrutiny. Most of the literature concerning this toxin was adequately summarized by Elek' whose able review must have convinced many readers that there was some paucity of definitive information regarding the toxin, for work on its purification alone was subsequently initiated in no fewer than half a dozen laboratories. The purpose of this paper is to describe somewhat selectively the nature and effects of staphylococcal alpha toxin leaving unconsidered much related information as, for example, the highly complex and controversial question of its significance in pathogenesis. Definition. Alpha toxin is a protein of molecular weight ca. 44,000, found extracellularly in laboratory cultures of pathogenic staphylococci, and produced in the course of naturally occurring staphylococcal diseases. Its classical biological effects are lethality, dermonecrosis, and in uitro hemolysis when appropriate test species of animals and cells are employed. The sensitivity of rabbit erythrocytes in distinction to those of certain other species, human for example, facilitates the identification of this toxin and its differentiation from other hemolytic products of staphylococcal growth. It induces the formation of antitoxin which specifically neutralizes the biological effects of the toxic protein. Production. Following the pioneering work of Burnet,' the Wood-46 strain of Staphylococcus aureus was and is used for toxin production almost exclusively. This strain is considered to form unusually large amounts of toxin, and although it unquestionably does, it might be of some interest to compare it quantitatively to other strains using modern cultivation techniques, and also to compare various stocks of this strain with each other. Much has been written about the necessity for optimal toxin production of long incubation periods, of agar, cellophane, COZ, and other substances. The need for these requirements is obviated when rotary liquid cultures yielding massive growth are employed, as shown by Alex Pinsky, in our l a b ~ r a t o r y , ~ using a medium free of substances of high molecular weight.